1
Get your hands on some saltpeter. Saltpeter is the common name for potassium nitrate. In the days when black powder was widely used, saltpeter was manufactured from bat guano or made from horse urine and other "manure soils."[1] It's used in many fertilizers, as part of science projects, and in certain recipes. You have several options for sourcing saltpeter:
• Look for "stump remover" in garden stores. Saltpeter is often sold under this name. You may also find it labeled as saltpeter, niter, or potassium nitrate.[2]
• Buy it online. If you do a search for saltpeter, you'll get plenty of results, and you can easily have a bottle delivered to you.
• Make it yourself out of a cold pack. Cold packs you can buy for a few dollars to help with sore muscles contain sodium nitrate and water, and can be used to make saltpeter.
• Make it with urine. This is definitely the most difficult way to source saltpeter, but some black powder enthusiasts prefer to make their powder entirely from scratch. To do so, one process is to fill a drum with manure affixed with a drain, valve, and filter at the bottom. Urinate into it, then top it off with water. After about 10 months, dry it out on trays.[3]
2
Obtain charcoal. You can use standard charcoal that you buy to cook with your grill, which you'll need to grind to a fine powder. If you're a purist, make your own charcoal by filling a metal drum with 3-inch pieces of willow or another wood, then placing the drum in a bonfire with a loose lid on top (to allow for airflow). Keep the bonfire piping hot for 4-6 hours, then open the drum. The wood will have charred into fine pieces of homemade charcoal, perfect for use in gunpowder.
3
Get elemental sulfur. This naturally-occurring substance is often used to acidify soil, so you can find it in garden stores or from online sources that sell garden supplies. Elemental sulfur occurs naturally and is mined from beds in Texas, Louisiana, Italy, and other locations around the world.[4]
Part 2 of 2: Mixing the Ingredients
1
Finely grind the ingredients. Use a mortar and pestle to grind each ingredient into a fine powder. Grind each ingredient separately, cleaning the mortar and pestle in between uses.
• You can use a ball mill to grind the components if you're planning on making a lot of gunpowder. A ball mill is used to both grind and mix powders safely.
2
Measure out the gunpowder components. Using the right ration of ingredients is very important when you're making gunpowder. Calculate the percentages by weight, using a small scale to weigh the different ingredients. Here's how much you need:
• 75% saltpeter (5 parts)
• 15% charcoal (1 part)
• 10% sulfur (2/3 of 1 part)
3
Mix the ingredients together. Place them all in the mortar and grind them together with the pestle for 10 minutes or longer. If you're using a ball mill, mill the charcoal and sulfur together for 4 hours first, then add the saltpeter and mill the mixture for another 24 hours.
• Be extremely careful around the black powder once it has been mixed. Do not smoke or light a flame anywhere close to the powder, and keep it away from heat.
4
Consider adding water. Some say adding up to 8% water can improve the gunpowder's burning. Continue mixing the gunpowder, adding water in small increments until the gunpowder is the texture of thick clay. Form it into a ball when you're finished.
• If you mix the gunpowder with water, you'll need to corn the gunpowder, or break it up into small pieces. Run the gunpowder ball through a kitchen sieve to break it into small pieces, then let the pieces dry out on a piece of paper.[5]
• Again, be extremely careful around the gunpowder. Exercise caution at every stage.
5
Store the black powder safely. Place the black powder in a special container designed for gunpowder. Consider storing it in a fireproof box in a shed or another area outside your home. In any case, store the black powder in a stable area where it will not come into contact with a flame or be exposed to high temperatures.
• You can buy powder containers at hardware stores or online.
• Some recommend using empty (unused) paint cans to store black powder.